Question

question 1 - 21
use the passage and graph to answer the following questions.
two biology students, noah and mateo, conducted an experiment testing the effects of intense light vs darkness on the amount of dissolved oxygen in an aquatic ecosystem. they placed two aquatic plants (java moss) in a tank filled with freshwater. they exposed the tank to each condition for 30 minutes, and recorded the percent dissolved oxygen using a sensor. before each experiment, they allowed the tank to sit undisturbed in normal conditions for 6 hours. a graph of their data is shown below. unfortunately, the students forgot to label their data files, so they dont know which plant was used to collect the data.
dissolved oxygen under different light conditions
which conclusion below is best supported by the data in the graph?
plants can only use cellular respiration if they are in the dark.
plants can only carry out photosynthesis if there is sunlight all the time.
plants can either use photosynthesis or cellular respiration but not both at the same time.
plants can switch between cellular respiration and photosynthesis in changing conditions.

Explanation:

The graph likely shows changes in dissolved oxygen under different light - dark conditions. Photosynthesis produces oxygen and cellular respiration consumes it. The ability of plants to switch between the two processes depending on light availability would best explain the data trends in the graph. Other options are too restrictive or inaccurate based on general knowledge of plant processes.

Answer:

Plants can switch between cellular respiration and photosynthesis in changing conditions.